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rdrand_sanitytest.c 3.3 KB

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  1. /*
  2. * Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.
  3. *
  4. * Licensed under the Apache License 2.0 (the "License"). You may not use
  5. * this file except in compliance with the License. You can obtain a copy
  6. * in the file LICENSE in the source distribution or at
  7. * https://www.openssl.org/source/license.html
  8. */
  9. #include <stdio.h>
  10. #include <stdlib.h>
  11. #include <string.h>
  12. #include "testutil.h"
  13. #include "internal/cryptlib.h"
  14. #if (defined(__i386) || defined(__i386__) || defined(_M_IX86) || \
  15. defined(__x86_64) || defined(__x86_64__) || \
  16. defined(_M_AMD64) || defined (_M_X64)) && defined(OPENSSL_CPUID_OBJ)
  17. size_t OPENSSL_ia32_rdrand_bytes(unsigned char *buf, size_t len);
  18. size_t OPENSSL_ia32_rdseed_bytes(unsigned char *buf, size_t len);
  19. static int sanity_check_bytes(size_t (*rng)(unsigned char *, size_t),
  20. int rounds, int min_failures, int max_retries, int max_zero_words)
  21. {
  22. int testresult = 0;
  23. unsigned char prior[31] = {0}, buf[31] = {0}, check[7];
  24. int failures = 0, zero_words = 0;
  25. int i;
  26. for (i = 0; i < rounds; i++) {
  27. size_t generated = 0;
  28. int retry;
  29. for (retry = 0; retry < max_retries; retry++) {
  30. generated = rng(buf, sizeof(buf));
  31. if (generated == sizeof(buf))
  32. break;
  33. failures++;
  34. }
  35. /*-
  36. * Verify that we don't have too many unexpected runs of zeroes,
  37. * implying that we might be accidentally using the 32-bit RDRAND
  38. * instead of the 64-bit one on 64-bit systems.
  39. */
  40. size_t j;
  41. for (j = 0; j < sizeof(buf) - 1; j++) {
  42. if (buf[j] == 0 && buf[j+1] == 0) {
  43. zero_words++;
  44. }
  45. }
  46. if (!TEST_int_eq(generated, sizeof(buf)))
  47. goto end;
  48. if (!TEST_false(!memcmp(prior, buf, sizeof(buf))))
  49. goto end;
  50. /* Verify that the last 7 bytes of buf aren't all the same value */
  51. unsigned char *tail = &buf[sizeof(buf) - sizeof(check)];
  52. memset(check, tail[0], 7);
  53. if (!TEST_false(!memcmp(check, tail, sizeof(check))))
  54. goto end;
  55. /* Save the result and make sure it's different next time */
  56. memcpy(prior, buf, sizeof(buf));
  57. }
  58. if (!TEST_int_le(zero_words, max_zero_words))
  59. goto end;
  60. if (!TEST_int_ge(failures, min_failures))
  61. goto end;
  62. testresult = 1;
  63. end:
  64. return testresult;
  65. }
  66. static int sanity_check_rdrand_bytes(void)
  67. {
  68. return sanity_check_bytes(OPENSSL_ia32_rdrand_bytes, 1000, 0, 10, 10);
  69. }
  70. static int sanity_check_rdseed_bytes(void)
  71. {
  72. /*-
  73. * RDSEED may take many retries to succeed; note that this is effectively
  74. * multiplied by the 8x retry loop in asm, and failure probabilities are
  75. * increased by the fact that we need either 4 or 8 samples depending on
  76. * the platform.
  77. */
  78. return sanity_check_bytes(OPENSSL_ia32_rdseed_bytes, 1000, 1, 10000, 10);
  79. }
  80. int setup_tests(void)
  81. {
  82. OPENSSL_cpuid_setup();
  83. int have_rdseed = (OPENSSL_ia32cap_P[2] & (1 << 18)) != 0;
  84. int have_rdrand = (OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) != 0;
  85. if (have_rdrand) {
  86. ADD_TEST(sanity_check_rdrand_bytes);
  87. }
  88. if (have_rdseed) {
  89. ADD_TEST(sanity_check_rdseed_bytes);
  90. }
  91. return 1;
  92. }
  93. #else
  94. int setup_tests(void)
  95. {
  96. return 1;
  97. }
  98. #endif